The present invention is directed to combination valve supports and sealing elements for filter cartridges. More particularly the present invention is directed to combination valve supports and sealing elements for use in filter cartridges, wherein the valve supports and sealing elements provide a bypass when filter elements within the filter cartridge are clogged and provide an anti-drainback capability when the filter cartridge is not actively filtering.
It is necessary and desirable for filter cartridges to have a bypass in case filter media in the filter cartridge becomes clogged so that the machine utilizing the fluid being filtered is not starved for fluid. For example, it is necessary for filter cartridges which filter lubricating oil of internal combustion engines not to block the flow of oil to the engine if their filter media becomes clogged. It is also desirable to prevent oil fluid from draining out of a filter cartridge when the fluid is not under pressure. For example, with internal combustion engines if the engine is not running, it is preferable to maintain oil in the cartridge so that when the engine is restarted, oil is immediately available for circulation.
During manufacture, when dispirate parts are matched, the risk of failure is increased because one of the parts may be of inferior quality and adversely affect the reliability of the entire assembly. It is frequently time consuming and therefore costly to assemble a plurality of elements in order to configure an item reliably. Consequently, utilizing only a single element can be advantageous. This is especially the case with mass produced items such as filters for engine lubricating oil which are manufactured by the millions.
In view of the aforementioned considerations, the present invention is directed to a combination valve support and sealing element for use in a filter cartridge in which the filter cartridge includes an annular filter element in a housing closed by an end plate, the end plate having a central opening surrounded by an array of spaced radially positioned openings. The combination valve support and sealing element comprises the unitary body of resilient material, wherein the unitary body has a central opening of a constant diameter which is coaxial with the central opening of the end plate and has an outer diameter less than that defined by the spaced radially positioned openings. The unitary body has a first section which projects into the hollow core of the filter element, the first section having a sealing ring thereon for sealing with the filter element. The unitary body also includes a second section coextensive with the first section which seals with only the end plate around the central opening through the end plate. The unitary body further has a radially projecting flange which is axially spaced from the second section of the unitary body and extends radially beyond the spaced radial openings for sealing around the spaced radial openings to provide an anti-drainback valve. A plurality of radially extending ribs are disposed on the radially extending flange, the radially extending ribs having rib portions projecting axially on the first annular section of the unitary body and being axially spaced from the annular sealing ring on the first section of the unitary body, which annular sealing ring deflects inwardly when the filter element is clogged in order to provide a bypass for fluid, when the fluid is unable to flow through the filter element.
In a further aspect of the invention, the combination valve support and sealing arrangement the radially extending portions of the rib support the filter element thereon;
In still a further aspect of the invention, the axially extending rib portions engage an end cap on the filter element and provide axially extending gaps therebetween, wherein fluid in the gaps applies pressure to the sealing ring, which pressure causes the sealing ring to deflect inwardly when a preselected pressure indicative of a clogged filter element is reached.
In still further aspects of the invention, resilient material of the unitary body is a rubber such as nitrile rubber.
In another aspect of the invention, the filter cartridge includes a filter element for filtering lubricating oil.